1. Field
One or more aspects of embodiments according to the present invention relate to the transmission of data, and more particularly to a system and method for transmitting data on multiple superimposed beams of electromagnetic waves with photons in different angular orbital momentum states.
2. Description of Related Art
Communication using free-space electromagnetic waves such as free-space radio frequency (RF) or microwave waves is common in various applications. In such a communication system it may be advantageous to send data with low error rates without using more power than necessary. For a single channel of a certain bandwidth, the data rate possible at a given error rate increases only logarithmically with the signal to noise ratio. Therefore, if a system with one channel is transmitting enough power to achieve a good signal to noise ratio, it may be more power-efficient to increase the bandwidth of the channel, or to add channels, than to increase the power in the existing channel. Increasing the bandwidth of the channel may in some cases, however, face technical obstacles.
Free-space communications may also pose problems related to privacy when, for example, confidential data are transmitted by a sender to an intended recipient, and a third party may intercept a beam of electromagnetic waves, and receive the confidential data.
Thus, there is a need for a system for transmitting data power-efficiently in a manner providing privacy protection.